var dataset = [{
		name: '蒸发量',
		data: [2.0, 4.9, 7.0, 23.2, 25.6, 76.7, 135.6, 162.2, 32.6, 20.0, 6.4, 3.3]
	},
	{
		name: '降水量',
		data: [2.6, 5.9, 9.0, 26.4, 28.7, 70.7, 175.6, 182.2, 48.7, 18.8, 6.0, 2.3]
	},
	{
		name: '平均温度',
		data: [2.0, 2.2, 3.3, 4.5, 6.3, 10.2, 20.3, 23.4, 23.0, 16.5, 12.0, 6.2]
	}
]

const width = 500;
const height = 500;

var state = d3.select(".bar").append("svg").attr("width",width).attr("height",height);
var update = state.selectAll("rect").data(dataset[0].data);

var enter = update.enter();
var exit = update.exit();

var rect = enter.append("rect")
				.attr("x",function(d,i) {
					return 50 + i * 50;
				})
				.attr("y",function(d) {
					return height - 50 - d;
				})
